Best available cop



Jan. 3, 1928.

B. Q. ISLER VARIABLE CONDENSER Filed Aug. 8, 1922 3 Sheets-Sheet l R M m M n w w M0 A m l m m g Jan. 3, 1928.

B. Q. ISLER VARIABLE CONDENSE R Filed Aug, 8, 1922 3 Sheets-Sheet 3 ierred embodiments of-my' invention and In- Which:

Fig. :1 is a .crossesectional elevationalview of my improved condenser,

Fig: 2zis a front elettational. view thereof,

Fig. :3 isaplanwiewithereof showing myimprorved resilient: supporting 'meansthere for; v

Figrea-is awiew-taken inmcrosssection on ,Eigs'fi is arcrossasect'onal. ehwaticmal yiew otla- 'modifidifomofzthecondenser; z-witli ipwrtszbroken-away;-..-.., 1. the-suma Fi isayiewshbwiin'g a p referred modification-oflthe mrmneriof mounting the rot tableiplate'setgzi Fig.=r9!1s a. vieyrishowi ing';aiconstruction 30 utilizedcineam improved manner of casting .the rotatable plaln set;-

Figs. 10 to 13 inclusive arei rieiwa showing the :miumers inz wliichi intenregisbrationof the 'ay; beiiobtained: whilezcompensating 1 vfobanycdifierential corntrawtimi.insncliipartsztukingqilacedurin'g r-the process t manufac- 'turemnds s. 145153; a: ioross sectional "vie-vii -'showing:amodificatiorrur-: i

cipalrihjedx of intention rOOmPIBlIQIldS the promssmnziofi fliwrmiablei in Y. whdhztheccapacityi zaliways uniform; for; a

gimengsetti t vdith acchmey ahdsshaxpness =end'rthe invention :inclndesithe: provision) of Ineansi ion-so: the 'movable .plate 0 able. plate set. is; 'automatica y and simultaneously taken ilp: :in thamuvmrehtnfi thesame. Where :the condenser isrzof. the. type I in which the-movable plate constitutes. a 3 "rotor-amt thastationary plate set constitutes 65: a: statogztheinventiomincludes; the mounta in graft-hm rotor shaft'in'conicalantl resilient endahearings in. such a manner. thatthesh'aft .is:.-eonti-1mous1y resiliently urged against and seated in the ends bearings .with lateral and 60 axial play-of the same obviated;..-

' Refierrmg now more in .detailto the drawings andstowFigszz-l m4 .thereoflthe condenseri comprises. the stationary plate set S preferably comprising: a unitary construc- 85 tion obtained by a die castingprocessand a fiyisiaihottbm; phnrviewot the samerotatable plate set R also-of a unitary construction, the plates of one plate sct being arranged in alternate relation with respect to the plates of the other plate set as is common in condensers of this type, the stationary plate set S being carried by a support including the end insulating plates and 11 which may he made, for exzunple of molded -hakelite or the like, the stationary plate set being secured to the end plates as by means of the-sets o'f-spaced securing elements 12 and 13 respectively inscrtihle through suitable bores in the end insulating plates-and receivable by suitably tapped bores in the stationary plate set or unit; as-

will clearly appear from the drawings; the

rotatable pla'teset or unit. R having the shaft 14' being-alsomounted in theend plates -10 'and ll by means of conical and resilienthea-rings. In the preferred c011 struetion the manner of -rnoamting the shaft 140i the rotor R includes the provision of a fixecl -or adjustable hearing for one end thereof and: a -resil iently mounted bearing forthe 7 other :end thereof; preferably both bcariilgs providing: 'toni cal: Seats tho correspondingshaft '-ends.R fcrring for example to Fig-.1 of the drawings, thepl-ale llis'provided-with an adjustable externally threaded-hearing element 15 adj ustahle in -an 7 internally threaded metallic insert'16 secured to the 'plate ll'during themelding of the the adjustablehemcing being: locked in anyadiustedpositiorr as by incense-f the-set screw 17- movable in the insert 16, the-said bearing element 15 being provided with a tapered or'conical seat 18; For cooperation with this conical bearing 15, the=sliatt is --provicled at its upper end with; a complemental tapered portion'or shoulder- 19':re-

ceivahlohy the conical seat 18 of the hearing '.'15.- The :taper ofboth the shoulder 19v and the seat 18may be made the same, gthe pro ferred construction, hOW'GVGE, including the r"0f;:tuning .-.t ehy madl possiblail To 'iihisl tapering of these parts in. different (leg-fees.

or amounts, as will he detailed hereinafter. Ina similar-manner the other end platelO is ;set.-with.:-:respect! torthe" stationary-= plate set thahlateral. as Wellies axiali'rlrilay oiithesmovprovided with-a conical bearing element 2-D provided with a. tapered. or conical seat or shoulder 21 COOPBPfltiHgWTltlI a correspondinglytapered .or conical. shoulder-or seat 22 providedin-the lower end: of the rotor. shaft the conical bearing element 20' comprises't-he the'male member with .the conical. seat22 vof the shaft the female member, itwill. h

'14. Although in the preferred construction .,resilient element'or spring 23, the latter atwtached-or Zanchoreduto the insulating plate- 10 asx-bywi'neans of one orzmo're Isecuring elements- 24 'anda25 receivable byi'. threaded iime'tallicninsents- 26. and-27 attached to the insulating plate;10; .Thebearing element 20"- may the secured: to :the .s'pring. 23 as by means wozf the threaded. shank 28 formed preferablyfwintegrallyzwith the .coni'caltbearing20', and a J nut,;29- receivable by the sha'nlc28. For

lamounting' the-condenser on any suitable supportzt33giand for rotating the movable plates theshaftlll 02E=the rotor is provided Y with i the reduced spindle ;portion 34 adapted for; :receivingrthendial: and. knob With wither proyisiorr offthisconstruction; it will 1 be seenthat Zinany position iof: the rotor R and during. rotation o'f-th-same,=the-shaft 14 is floatinglyacarriedaatzone; end by; the; spring bearing;,--and;;the shaft-urgedbyL-the action 1. 2 0i thei -;springr-lo'earing willi :rbe' resiliently seatediimthiopposed'ehdbearings 15' andQU i fii hiua'll afialandalatral --pla.y;'- otthe shaft Band tio'tor efiettitlyneliminated while; protdueing nniformity: loflgffifiotion' between the 3Q pints, ro ztioriro fi tlieimorvabllez plate set being 7 tlrusphtainablinyithoutfithat Joosene-Ssmnd eirol-lil g action qfiv ihorshalft; incthe bearings ni icidentw liostheg 1.18m (ii J:pr10r .-1condenser 'nQ nSfi illqQQl bne ,aeieh; {iiiifiJli'iii-i ed;

. guniiorm {frictional imovementjpf the:movable gp12 i t e. set in(all condensers; in spite .of the -unavoidable manufacturing-v variations, in the {,anglemiittrper oiitheib'earings so'asto secure if" !mfi (ith and; eveinturning and steady-.balancriingwofizt eisaid mo able-plate Eset uniformly ailitf llrwnden fsyitli ishaflr oi ;the "rotor is ripre qmbl 'eso amounted-yin? the bearings as; to .-prov de;; oriand insureyaa constancy of, the

-r ht lxzsa lg plis da\inraemanner;Ehereinbejore referred :to, ;byrpro'ducing' 'an unequal or Ld fierentj degree-of taper for the complemen- -.th e ifrictignal-len'gagement between" the same take {plac On, aline; as;.rdistinguished -froni a silrfaceg withi the'said'line' forming a .cu i; ve 6f=;constant Iad111S..: This is shown-parfi kshoul en19- andthe tapered seat -18-'- being .produced at slightly. idifierenaiangles, the

' tapers being so chosen that the contact be tween thegshaft 14 and the bearing 15 occurs .only, on a line of constant radius. The

9 difference; in taper is somewhat exaggerated in the drawing-it being understood-that the difference in the angle of taper may be about one or tWokleg reesr Thevotherrend: ofthe shaft 14 is similarly provided withitheconical seat 22 cooperatingwith tllGzCOIllGfijl or" tapered shoulder 21 of the conical bearing element the taper here being-alsoso produced as to form a line contact'bearing of constant radius; Although I prefer'zto provide both the shaft and the bearing element with a straight sided taper as shown inthe drawings, it will beapparent that other contours-may be equally feasible'for producing the line contact of uniform radius. lVith the particular construction shown, moreover, am enabledto secure a large radius ofcontact, this being more desirable to permit of a proper balancing of the movable plate-set with the aid of: a-lighter' spring than-would be needed with a smaller frictional' radiusf" the movement or lengtlr ofpa rtsifromiseriously changing the tension, 0t lthe spri-ngaaiid effecting 'a permanent set:therein; theinomfial deformation thereof-must: be large,a'requiring a, relatively thin springih'a'vin'g. adorig effective stress-path. i In a. small condenser ofithe' order 0f"0.001 microfarad s; :howeveriilthe space limitations prevent the employment'of long springs;v A desideratuin,therefore, is to provide a spring having combined'along effective stress path and -com'pactness.= Moreover, in order to perform proper-servicefion a 'movable condenser unite to 'effectivelyitake up lateral and axial; play thereof, theispri'ng should be constructed t'o-give relativelylhe'avy pressure.- Furthermore; in? order to prevent any-liability of tilting of theshaftandtrotor plates so thatnon-parallelism of the stator and rotor: plates with consequent: danger of short circuiting at the edges may be a'voideid,

force of application ofwhich' isi e'xeited directly axially of the rotor-shaft. a To attain all theseends, my present invention includes the provision of a resilient.meansihavingga point of application active on' thelrotor shaft I make use of and employ the spring device" it is highly desirable to provide a spririgrthd 23"hrctoforereferred to and. shown particularly invFigiz: 1 to 3 ot-th'e drawings, the said spring;- vice conveniently taking the form ofia sheet metal: disk provided withthe substantially parallel elongated slots 0, and bsubdividing the disk into a central portion 0 attached to the shank 28 of the bearing elelIlBIltQO and active thereon to produce the spring piessure, and exterior portions d and e anchored at spaced points to the-insulatingplate 10 as by means of the securing elements 24 and 25 heretofore referred to, the construction being such that aplurality of stress paths are active from each point of anchor to. the point of application of the ipriiig with'each'stresspath such as indicated by the dotted line a: in Fig. 3 substantinlly greater than'the distance between a point of anchor was 'point of application. Moreovfer,sit.will be noted that the stress/paths are symmetrically arranged about an axis of the rotor-shaft so thatthe force applied to the shaft isrdirectlyraxially of the same. Ituzill be'-seen,;furthermore-, that y Pmwidinga "-a' strong eli'eotive spring-pressure plurality :ot stress path-s; here four numbers, active on the rotorashaft' is obtained. i j

s-Foratlie purposeifot producing an ciiicient i electrical ricoitmetzt ion tout-he rotor-plate setandsto thezshaftrthereof', my'invention turither. iicornprehends i .ai'1construction:-. in which 2 the 819011110311COIIIIBCUOIIF'IS' made directly tronntheishaft to a-connecting terminal without. thevintermediation-zot the springor any other member, this producing a structure in Whichthe-liability of open circuiting'due to 'loosenesslbetween the parts 'is reduced to a minimum andcfi'ective electrical contact is obtained. To these ends.- the connection to the rotor/shaft 14: is made directly-by way of the conical bearing element 20, and referring tosFigs: l tea-3 of the drawings, I show the shank.:28 threaded." to; receive a binding nut 36,-1he1 tWQcOnStituting'a binding post unitary with the conical bearing For: providinsgiforrelectrical connection to the stationary plate set S, said plate set-may be'provi'ded withzthe threaded shank=373 forming in conjunctionwithtthe lock nut-35 and binding nut 39 :a1 second connecting terminal;

* Asbeiom' mentioned, the rotor and stator plate sets of: my condenser, each? of whi'ch maybe prtivided with one or more plates, are preferabty made of a unitary construction and preferably obtained by casting the same as by a die-casting process. In casting the rotor plate set, I have'found it very desirable in order to obtain strong-and durable end bearings and a reinforced construction to castthe unitary plates of the rotar about-a central spindle which in the resulting con- Struction forms the shaft 14 of the rotor, the said spindle or shaft being made of a 'metal different from and having a higher 1 melting; point than. the metal. forming. the

during casting of the movable plates, and to provide a more rigid rotor unit, the intermcdiate portion of the shaft 14 may be reduced as shown at 42 in Fig. 9 of the drawin s, the reduced portion being provided wiai the roughened or'knurled sectionll to'prevent the turning of the casting on the shaft For the purpose of limitin :axial movement of the; shaft against llie action ot spring 23 to prevent abnor mal deformation thereof and to prevent short'cnouiting of the plates, the shaft 40 is preferably extended to provide the shoulder -l0 whicl'icooper'ates with plate 10 to act as a stop'to limit-such axial motion, the normal clearance between the plate and shoulder being slightly less than the clearance between adjacent plates.

In a condenser of thewariabl'e; type, 'i'tis highly desirable to'provide' for-"a small minimum capacity when tl1e plates "ar@ out of capacitive re a'tion with-each other Mid td further provide for-a gradually increasing rate of increase incapacity as the mot able plates are rotatedinto capacitlve relwliion with the stationary plates, and toprovidefor a maximum capacitywhen the platesar e in maximum capacitive relation with a maximum economy of space To accomplish these ends, my present invention incl des a construction inwvhich the stationary and movable plates 'a -e'cut away at one side only of the axis ot-the same 'with the coh'structinn such that the movable and'stationary plate sets when in full ca aeitive relati'en with each other are cut-away at-thesame 'side.

Thisis-fully shown in Fig. 4 ofthe drawingsf'n and referring to this figure it 'willibe seen thata plate of the rotorv R'differs'fi qni-"a sub stantia-l semi-circle by beingcut away along the line t?) at an angle to araflius etithe plate, the cut-away :bein th'eretdre directed inwardly of the plate withithe dee ea ortion of the cut-away at the central part ofthe plate, and a plate of. the stationary plate-set S is similarly. cut away at the-"corresponding side along a line 44 alsopreferably aean izo angle to a radius of such plate; lVjitjh this construction a smallmi'ninium capac'i't' is obtained, a gradually increasing rateo increase in capac'ity'is effected-as the rotatable plates are moved into capacitive' relation with respectto thestationary platearancta maximum capacity is obtained combined with a maximum economy of space. I

' Referring now to Figs. 5 to 7 of the drawlugs-,1 show a modification; of myirwention provided throng in "which the rotor R provided with the shaft 45 is suitably journalled in end plates 45 and 47 which-in this instanceam full cir-jj cular'pla-tes as contrad-istinguished' from the form shown ilr-Fi'gs'; 1 to 45, the said end plate'sbeing provided with the. conical 'bearing' elements 48and 49 similar to the conical bearing elements heretofore described-{with reference toFigs: l to 4;" In the modified construction, the stator "set of plates S" is fixedly sn'pportedon the end plate 47 as by means of the symmetrically spaced securing elenients 50, thestationai'y' "plate castingbeing provided with the oppositely positionf ed extending arms 5 1 (one of which appears in'Fig. providing-'the spacedbosses or posts 52% receiving the securingelements 50, jth'e' said stationary casting 8' being floatingly=orresilientlyEmourited on the opposed end "'Iilat 46 asa by means of the spaced securing elements {53 receivable byand secured' to the spaced'bosses 54 provided inthe extending arm's ts integraliwnh thesai'd s't a tionairy plate fch'tingg means saf-beimg in's'ftabl'e 56' provided in the p'latei46," a resilient .ele-'- ment i'such as" a; compression sprin 570 chofe'd at oneIioint tothe"'s'up or ting plate 46'andata'nother pointtda was 61- 58 nga -i ing tlihea'l' 'of thesecufiii 'heans 53being provided ior each securing means '-f61 exerting' -a halanced 'tension 'on' the iate 46 to produce the desired resilient--= fof;

thermos-plate 'se't R; in thi si-form -oi my inventiong' theifore, V in Figs. to' 4-, resilient and cohji'calfbear mgs are provided-for taking'iip all lateral and ti' '-I Ii*thi s form of the inventiori'als6 the bearing "element 48 te'r'iiiinal dl. this-end;

axial 1 play of the rotor "sh'a majy constjqiit'e t1r connecting binning pa eroattiie' fotbrg apd v the i be? ring eIeiiiTe'nt inchides th threaded pqa fmaane statioiia fy pllite sfiksfi'sshowfii strs are: cilig in Figfifi ef tha diaaihge me biaaing pa e 61 connected to thestationary plate casting as injthei forin shown inoldi'ng' fii i t l lidPl s. fl t omi is'ion to ecure-p oper;re istration of the pla' teset, the. preferred'consti'uction incln la-i 1at'5setsihereona T6 myomwms difiiculty Janincrease in cost while at the same-time providing for" proper registration of the *condenser parts, the present invention 'in- 'cludes"the molding of elongated orifices on :the end plates so arranged as-to'compensate for any'diflerential contraction or expansion of the parts taking place during the process -o.t manufacture, while still permitting the obtainin'gofproper alignment and centered positioning of the end plates on the conden- I 'ser plates castings during assembly. To this end, referring to Fig. 10 of the drawings,'the -orifi'ces 63,,"64 and-'65, inboth' of -the e'ncl "plates such as the rear end plate '10 are jelon gated" and are disposed approximately 'radi ally of the plate '10; the arrangement being such, that the direction of; bodily shift'of'the orifices will be mainly along the directionin which they-are elongated ,'"so that the centerj" of the bearing will; not be shifted serionsly,f 'and'so-ithat 'changein the distance between the 1 orifices which would, plie'ventj assembly entirely if the samewere round 5' aiid' of, the 7 "corre'ct diamet'er to fit 'th e-fl-securing means .received thereby will'- haye no fletriinnta-l" *f'efiec't in-xefiecting" intefiegistrationjdf tliei- 'parts. Thef-a'r'rangemeiifl of thei elongate 'orifices'fijis' flirthrmorefsuh that the two? 'npper wine's-issued; 65fifx' th-i 'osition o' tered position is th g e th preferied i the provis on i' ontm 12 of-the 'aawing y anaji eirgingj "ing' the p'i'oyision of tenon'membeifsior' teats" 66 provided in; thel ,end' plate siichasj the end".

-' "plate "11' cooperating wimimortises1orfre i cesses 67 provided in the spaced posts 68bit" "the I condenser casting; 'Ihjef inortises land tenons are preferably'tapered or"'made coni-' cattle s own, and th m r os e 'prefer bly elongated and arranged approximately ra dially of the casting as c ear y shown in t e aw gs, t s to the end f comp nsating for any differential movement. bet-ween the pa t taking place. du i g manufac ur As shown in Figs. 11 and 12, the securing elements such as 13 are thi'eadedly received by e. pos 68 and are ecei ableiby enlarged orifices su h as 63, 64 nd 65 which met ehly are elongated as. described- For the purpose f minimizin to imperfect, dielectrics. in the Electrostatic eld of the condenser, he spring Whl9ll S P- ports the rotor may h 'mounted on the end p ete as shown. in F g, 4 of the omwing'e s-shown in is. figure the supporting epri s, attached. o the in ei ior, as distillguished from he exterior side of the end p ate 1.0 by means of the se ring s e 24 and; 2.5, his t the end of removing the dielectric offered b the end plate from theel otrosta io-fie d. bet een the sp ing 23 anglthe stator-plates S- e sp ing 23 enrieethe conic l hea ing. and e inte 1 bi din ,st. 28, e s .acing sl e e 69 refit ed by t lifirifioe 70 the pla 1 bein pro ided; or spa ing the e men o he: indiiigipoet from the pringv 2 n this modif ation the spr ng 23" also. serv s ilimitye iel movement of the shaft, he,

spacebetw en the spi' ng and theend floto 10 being made somewhat less than the mom'- n o between adjacent lates! The-manner of making and l sllig m im-. proved Condenser will in the main be apparent from the above detailed description thereof. It will be further apparent that by the provisiitm of the various improvenients endfl he n err lation thereof, that I have provid d a conden er hich. is EW to einiQlioijty of manufacture, ease. 01t- 3 113;

31, eptt efiieieney of. peration, the page nih niii t prohti e t= stro compact. and eatc n .e ser' nit having 5i halnieal tind'e ect i'oel c ei acterist est Although I ave. shown} my d vice inthe p1eietred'.f, orms, it will'I be apparent that a riety of modifipetions meyhe m de without ep rting rom the spi it of he i e i n- 'l -fivil ibe; apparentgfor example, th

either plii'te: set mayiconeist f one. o m

plates, and where lhz i e used; in, thefollow ing el'aims the expression plute set? I desire ittto be understood to apply to a const-ructi'on in, which either one: inore plates is used, It. will further beepparent-that in lien of providing a1 straigh taper on the. bearing. or in the interregistering means that the. contour. may be changed and made in a variety of ways 'wit-houtdepartin from the, new reeults achieved. It will be iirtlier apparent, for example, that. the resilient supporting meansv of my. invention may be modified in a number of ways without (le- (Y lessee due e desired mebeatings sothat;

p rt g from the'pri ip invo ed therein. It ill e al o nderstood that. many oi the features o my invent on,,while-eh W 11R- p iod to e e rical condensers, e e oo lly applicable to other precision instruments Where similar pmblems are invo ved, Such 1 for example as in .var'iometers, variotr-an formers and the like, and Idesire it to be td rstood th t e. ope decl la ms are intended-to be applicable to. ouch equivalentpreei io m numents, It will be teen hat numerous ther modifioationa mey' 'bemed without d parti g iromthe spirit-of the ntioi definetlin the iollewingtoleimei I 1. A con ensermp ising o st tor .glett set-,- a rotor plate, set, enclmean i 11. Bow

porting I the rot r, Pla set for: mo ementrelatively to the plete-:setinelnc i g oppositely ac ing hearin'ge on he;.eh ft-- of the. ro or plate s one e; tapered bearing for ope-side oli; the and the other eoi-npriemg a spri-pg. beefing;

resiliently carrying; hevother eide t-the shaft and. floetingly' supportigg axially and; laterally; and mo iv or--=e &

tinuously unging thesame age inet hetepeit axial play oi: the roto nee simnltaneoufi y of the s me mprising a stator, m o 'or end pla es-oer i'ied. by the. statons hd mou t-rim support ng;

the roto in said ehcl. pla sysaid meansxoem prising 'a bearing. o one side o :th moto s aft car ied by one -of th end ,ploteeia silient device supported-.onetihe: othen oiled plate and pt yitledsv ith a; he emgearra iged. i

to fioatinglyear eod-rg portethegoppo te it the ,game

3-. A co denoe f-ieo iiii lifigiihi i-e t ir,

.e roto end: p ates oer iedv'. by-i heietfitdr z-node; means for swporrtmg 1 the roto on: iseid 15;

tapered bea ing por ions, :ehea' ing oemrier y one of he. p teseand providedmi hwa t penet tea for one of .seigltaperegh beere: 111g portlonst beati g rmhhn the-ethe p ate. n also bearings to e och the s ing f he otorshaf n; bothI- oermge? 4. In a. dev1 e of the o assie eeeribetL-e ,oontim oue t es lient stator, a. rotor, d lates carried" h the I su tor, and mear s forsupporting the re 1:. in, said e d. plates includinga rotor shat-t having spaced tapered bearing portions, a beefing; l

- of :t e vi im eql-uh eta anh isetti igs'o i J.

proyided with :o tapered. seat carried by one of the plates and provided with a tapered seat for one of said tapered bearing portions, a substantially flat-shaped spring device carried by the other end plate and a bearing on said spring device also provided with a tapered seat'for the other of said tapered bearing portions, the said spring device being active on its bearing and adapted to effect a continuous resilient seating of the rotor shaft in both of its ta ered bearings so that both lateral and axial play of the rotor are taken up at each settin of the same.

5. in apparatus of the class described comprising a stator, a rotor, and means for supporting the rotor for movement rela tively to the stator, said means comprising oppositely acting bearings for the shaft of the rotor, one comprising a bearing for one sideof the shaft and the other comprising a spring device provided with a bearing resiliently carrying the other side of the shaft and fioatingly supporting the same axially and laterally and active for continuously urging the shaft against the first-mentioned hearing so that both lateral play and axial play of the rotor are simultaneously and automatically taken up at each setting of the same.v

6. An apparatus of the class described comprising a statorQa' rotor, end plates carried by the stator, and means for supporting the rotor in the end plates including a hearing for one end of the rotor shaft carried by one of the end plates, a spring device anchored at a plurality of circumferentially spaced points to the other end plates, a bearing carried by said spring device fioatingly carrying and supporting the other end of said rotor shaft both axially and laterally, the

said spring device being active on its hearing to effect the continuous resilient seating of the rotor shaft in both of the bearings so that both axial and lateral play of the rotor are taken up at each setting of the same.

7. In a condenser, a stationary plate set, a movable plate set and means for movably supporting the movable plate set comprising a bearing adapted to engage the shaft of the movable plate set and a spring device carried by said stationary plate set carrying the said bearing for floatingly supporting the shaft both axially and laterally.

8. In a condenser, a stationary plate set, a movable plate set and means for movably supporting the movable plate set comprising a bearing having a tapered seat adapted to engage the shaft of the movable plate set and a substantially flat-shaped spring device carried by said stationary plate set, the said spring device carrying the said bearing for fioatingly supporting the shaft both axially and laterally.

9. In a condenser, means for supporting a movable plate set comprising a bearing element having a tapered portion for forming a bearing seat and a shank portion for forming a connecting terminal; and a spring element carryin the bearing element.

10. In a condenser,

tioning one on the other comprising a plurality of spaced tenons on the one and a plua plate unit, a supporting plate therefor, and 'meansfor posi- 

